Archive the father as well as the mother; how many represses a mother carries

Decided (October 2026): the plant keeps the father and the mother of every
side. production-timeline.md (repress section) records the decision and the
rule of thumb with sources: about 10 stamper sets per mother before it
degrades (Third Man Pressing FAQ, a Nashville plater via WPLN), fewer in
quality-minded sources (5 VinyLab, 6 to 8 Stereo Review 1962); a father
grows about 5 to 10 mothers. So a mother covers roughly ten represses
(10,000 to 20,000 records a side) and a worn one is replaced from the
archived father without a new cut. galvanics.md: 4 archived parts per
title, ~1,200 to 2,400 a year; new open question to all galvanics
candidates (sets per mother, mothers per father, storage).
artist-platform.md repress paragraph.

Demos: make-a-record and artist-order say father and mother are archived;
factory console archives the father on represses too, counts stamper sets
per mother (shown in the genealogy and the customer's metal card), and the
metal archive counts fathers and mothers.

docs/artist-platform.md

@@ -367,7 +367,9 @@ vault for a second attempt.
 
 ### After the first run: repress on demand
 
-Once a title exists, its mother sits in the archive and a repress takes
+Once a title exists, its father and mother sit in the archive (a mother
+gives about ten stamper sets, and a worn one is replaced from the father
+without a new cut) and a repress takes
 **1.5 to 2.5 weeks** of plant time
 ([production timeline](production-timeline.md)). The campaign page can
 reopen as "pre-order the repress, pressed when 100 more are in", which